Mold



Juy 2, 1935. F. A. BRIDGETT 2,006,666

MOLD

Filed Dec'. 9, 1933 2 Sheets-Sheet l Inde/o r.- Frank, rzzqye,

July 2, -1935. F AA BRlDGETT l12,006,666

- MOLD Filed Deo. 9, 1935 2 sheets-sheet 2 1 l l l Patented July 2, 1935 UNITED STATES PATENT OFFICE 16 Claims.

My invention relates to improvements in molding, especially molding in which the mold cavity is formed by a plurality of cooperating mold elements.

The purpose of the invention is to provide improved method and means for molding objects having intricate surface formations or contours, such for example, as replicas of the bones of the human or animal skeleton.

The invention comprises mold elements, each having recesses or indentations which cooperate in forming a mold cavity corresponding to the object to be molded or cast: The said mold elements adapted to have relative separating movements in directions that will permit the withdrawal of the mold elements from each other and from the object which has been cast, so that the object with its intricate surface formation shall be unimpaired.

In furtherance of the purpose recited, the invention also comprises mold elements having reciprocal contacting surfaces, surrounding and adjacent the cavity, undulating to correspond with the predominant marginal contours of the cavity.

As illustrative of the invention, I have shown the same applied to the molding or casting of the temporal bone of the human skeleton. It will however, be understood that the invention will equally apply to the casting of other objects, especially anatomical, having intricate surface formations.

Referring to the drawings which illustrate, merely by way of example, suitable means for effecting the invention:-

Fig. 1 is a perspective view of a mold comprising three elements.

Fig. 2 is a similar view on a larger scale showing the two lower elements with the object cast associated therewith, the upper element being indicated in broken lines.

Figs. 3 and 4 are fragmentary sections.

Fig. 5 is a perspective view showing two elements and the cast object and the manner of separation.

Figs. 6, '7 and 8 are perspective views of the three elements showing the cooperating recesses therein.

Similar numerals refer to similar parts throughout the several views.

In the present example the mold is shown as comprising three elements 9, I0 and II. Each is provided, as to its interior, with recesses and indentations which, in cooperation with the other elements, will formthe cavity in which the object I2 is to be cast.

These several recesses may be formed in any suitable Way, for example by forming preliminary casts or molds in plaster Paris, or the like, about the original bone, or a'pattern thereof,

material, by cutting or carving out the recesse's of required formation.v

In` forming these-mold elements, it is essential that the surfaces of engagement and separation of the respective elements be so formed and related to the major or predominant margins of the casting to be formed in the mold cavity, that the said elements Will be separable from each other and from the casting, without marring said casting or Ythe adjacent surface walls of the mold elements. In the present example, the several elements are separable from each other by initial relative movement vertical to the plane of the base. This initial vertical movement is secured by the means employed for securing their proper association and register; d

as for example the projections I8 and corresponding recess, as shown in Fig. 2, or by the dowel-pin and recess I9 in Fig. 3.

For example, in separating the mold elements from each other and from the casting, element 9 is rst initially moved in direction vertical to the plane of the base. It is then entirely removed from the elements I0 and II and from the casting l2.

Element II is then moved initially in the same vertical direction and carries with it the casting I2, away from element I0, as shown in Fig. 5. Element I0 is then free to be entirely removed, and the casting l2 may then be dislodged from element I I by a tilting or pivotal movement, which movement is required due to the peculiar curved contour of the major face of the cavityl in element II and also to the embracing curved formation I2 representing the zygoma which forms part of the casting.

In the operation of casting, two methods are common, namely the extrusion method and the positive method. Y

The extrusion method may comprise the hand mold method in which no pressure chamber is provided, but is merely provided with a passage or passages of suitable dimensions forconveying y the material through a mold element to the cavber, or cylindery I3 associated with the top uf element 9. This chamber is provided with the material Which is to be forced into the mold cavity. A channel I4, centrally disposed with respect to the chamber I3, .passes through element 9' and delivers to cavity adapted to form the casting or object I2.

A plunger I5, see Fig. 3, is adapted to enter Vthe top of chamber I3 as the mold is raised in the usual Way relatively to theV plunger. In this Way the material is forced fromthe pressure chamber into the cavity under sufficient pressure to insure a complete filling Aof the cavltyandthus securing va perfect casting. During the casting operation, the mold element mayA be maintained .at required temperature-by means, for example, of channels I5 passing j through the element 9, and ysupplied with steam or lother temperature- Vcontrolling medium.'Y

chamber I3 may vbe associated with 'the mold in any suitable Way: For exampleA in F'ig. 3, :it-is'lshown as integral with the-moldelement 8, Whilein-Fig.- 4, it is shown as I3'., removably threaded into an annularchannel or groove I1, provided in Vthe topof the mold element.

'-I-he advantage iof thevrremovable pressure chamberis that, -Without the chamber, the mold may be used asa hand mold., V

It willfbe understood that, depending Vupon the charaoterof the casting, the number-of elementsv Vmay be-increased-orreduced, as required.

l'I'he'outside :dimensions of the completed mold may be such as to adapt it for use 'with'ithe Hplatens or-other -parts of standard machines. f

As to the material suitable for the castingit should usually be plastic, such, for example, as the synthetic resin compounds of the thermoplastic and thermo-setting types, rubber, glass -or thevlike. Y

The method and means `for casting herein ,shownfis especially adapted for making anatomical exhibits, in which, not only is the replica of the bone` produced, as to its lexternal surface contours, but such ex ibit may atjthe same time comprise, for example, a bone `formationfwith -another for-mation encased therein; this'interior f ormation.-being previouslyY cast and suitably positioned in the `mold lcavity before introducing the .material thereto. ,v :The encased Yformation is, for example, of material of higher fusing point `than that of the surrounding material, and suitable means, such aswire 2|, is provided Vfor supporting said formation :inthe cavity during theV introduction lof the enveloping material. i v In this wa/y, for` example, certain nerves 'and vv.nervechannels, such-as the labyrinth 2B, Fig. 2, made yof opaque or non-transparent material, Ymay be enclosed in a surrounding casting, representing the bone, of transparent material, so `that ananatomical exhibit may be produced, in which the relation betweenrthe several vformationsmay be readily seen from every side.

l. An anatomical mold structure comprising a composite body portion formed of a plurality of mold elements having recesses combining toform ra. castingcavity, said elements having complementary contactingfacessurrounding and adjadulations throughout their entire` areay to cor- ,respond withthe predominant marginal-contour of the cavity.

2. An anatomical mold structure comprising a elements having recesses combining to form a casting cavity, said elements having complementary contacting faces formed with undulations throughout their entire area, said undulations lextending to the undulating'predominant marginal contour f the cavity whereby to facilitate separation of said elements from each other `and from the casting and means associated with Y said surfaces for cooperating inthe proper assembly and register of said elements and to secure preliminary movement of separation along definite lines of travel.

3. `A:moldl'i'avinga casting cavity with intricate surface and marginal contours comprising a plurality of mold. elements having complemen- -taryrecessesfcombining tozform said cavity, `'each f `-said lelements having surfacesfof separation formed With undulations corresponding to fthe undulating ,predominant marginal contour vofV the cavity, -saidundulations extending to the-y `undulatingpredominant marginalcontour-of the cavity whereby fto facilitate separation ofthe mold :elements1from 'each 'other-and from the casting. c 1

A4. A mold having aca'sting cavity'with lintril cate surface andmarginal contours, comprisingk -a plurality of mold-'elementslhaving complementary recesses' combining -.to form'said cavity, each `of Asaid elements fhaving 2a por'tion vof their stir-' faces kof separation' formedwithundulations' cori responding to the undulating preiibminaiit vmalr- `-ginal `contour fof the cavity, f said fundl'atioras extending tothe undulating predominant marginal contours of the .cavity ivvli'ereby vto 'facilitatef`separationdof the mold elements from :ea'c'h other and from kthe casting. Y i 5. A mold having Sa casting cavity with 'intricate surface and 'marginal contours comp'rising three mold `elements having icomple'mentary recesses combining to form said cavity, Veach ef :said .elements k"ha-ving. surfaces-of .separation formed `with unduiations corresponding to the `undulating predominant marginal ccntourof'the cavity, said undulations extending 't'o `the undulating predominant Zmarginal contours-of the mold elements from each other and from the casting. Y

f6. LA Vmold having 'a kcasting :cavity with #intricate surface andV marginal' contours, comprising Mthree vmold Velements having Irvcomplemeritary -recesses `combining to fom'n fsaid cavity, each 'of Y said Velements aha-ving fa portion "ofitheir surfaces ary `recesses'combiningto form said cavity, `each of said elements having surfaces of separation 50 formed with undulatiis Il:oresporiding'V Vto lthe 'undulating predominant marginal contour of the cavity, said undulations extending to the undulatingpredominant'marginalcontour of the cav'- ity whereby to .facilitate yseparation 'of ythe'nasal i@ elements' from each other 'and from the'castng and means to secure 'preliminary movement of separation or `I'lhe .claimants along definite lines of travel. i Y -8. AA mold :having a caetmgeaity with 'intricate surface and marginal contours comprising three mold elements having complementary recesses combining to form said cavity, each of said elements having surfaces of separation formed with undulations corresponding to the undulating predominant marginal conteur of the cavity, said undulations extending to the undulating predominant marginal contours of the cavity whereby to facilitate separation of the mold elements from each other and -from the casting and means to secure preliminary movement of separation of the elements along definite lines of travel.

9. A mold having a casting cavity with intricate surface contours, comprising a plurality of mold elements having complementary recesses combining to form said cavity, each of said elements having surfaces of separation formed with undulations corresponding to the undulating predominant marginal contour of the cavity, said undulations extending to the undulating predominant marginal contour of the cavity where-- by to facilitate separation of said elements from each other and from the casting and means associated with said surfaces for cooperating in the proper assembly and register of said elements, comprising projections formed on one of the surfaces of separation of an element and corresponding recesses adapted to receive said projections formed in the separating surface of another element.

10. A mold having a casting cavity with intricate surface and marginal contours, comprising a plurality of mold elements having complementary recesses combining to form said cavity, each of said elements having a portion of their surfaces of separation formed with undulations corresponding to the undulating predominant marginal contour of the cavity, said undulations extending to the undulating predominant marginal contours of the cavity whereby to facilitate separation of the mold elements from each other and from the casting and means associated with said surfaces for cooperating in the proper assembly and register of said elements and to secure preliminary movement of separation along definite lines of travel. Y

ll. A mold having a casting cavity with intricate surface and marginal contours comprising a plurality of mold elements having complementary recesses combining to form said cavity, each of said elements having surfaces of separation formed with undulations corresponding to the undulating predominant marginal contour of the cavity, said undulations extendingr to the undulating predominant marginal ccntour of the cavity whereby to facilitate separation of the mold elements from each other and from the casting and means to introduce material to the cavity comprising a passage connecting said cavity with the source of material to be introduced.

l2. A mold having a casting cavity with intricate surface and marginal contours comprising a plurality of mold elements having complementary recesses combining to form said cavity, each of said elements having surfaces of separation formed with undulations corresponding to the undulating predominant marginal contours of the cavity, said undulations extending to the undulating predominant marginal contours of the cavity whereby to facilitate separation ofthe mold elements from each other and from the casting, one of said elements having a pressure chamber formed therewith and means to introduce material to the cavity comprising a passage formed in said element between the chamber and the cavity.

13. A mold having a `casting cavity with intricate surface and marginal contours comprising three mold elements having complementary recesses combining to form said cavity, each of said elements having a portion of their surfacesof separation formed with undulations corresponding to the undulating predominant marginal contours of the cavity, said undulations extending to the undulating predominant marginal contours of the cavity whereby to facilitate separation of the mold elements from each other and from the casting, one of said elements having a pressure chamber detachably secured thereto and means to introduce material to the cavity comprising a passage formed in said element between the chamber and the cavity.

14. An anatomical mold structure comprising a composite body portion formed of a plurality of rnc-ld elements having recesses combining to form a casting cavity, said elements having complementary contacting faces surrounding andadjoining the cavity, a portion of said faces being formed with undulations corresponding to the predominant marginal contour of the cavity and extending to the undulating predominant marginal contour ci' said cavity whereby to facilitate separation of the mold elements from each other and from the casting.

l5. An anatomical mold structure comprising a composite body portion formed of three mold elements having recesses combining to form a casting cavity, said elements having complementary contacting faces surrounding and adjoining the cavity, said faces being formed with undulations throughout their entire area and extending to the undulating predominant marginal contour of the cavity whereby to facilitate separation of the mold elements from each other and from the casting.

16, A mold having a casting cavity with intricate surface and marginal contours, comprising a plurality of mold elements having complementary recesses combining to form said cavity, each of said elements having their surfaces of separation formed with undulations corresponding to the undulating predominant marginal contour of the cavity, said undulations extending to the undulating marginal contours of the cavity whereby to facilitate separation of the mold elements from each other and from the casting, one of said elements having a. pressure chamber formed therewith, means to introduce material to the cavity comprising a passage formed in said element between the chamber and the cavity, means associated with said surfaces for cooperating in the proper assembly and register of the elements and to secure preliminary movement of separation along deinite lines of travel and Ymeans to control the temperature of the mold comprising a plurality of channels formed in one of the mold elements adapted to receive a temperature controlling medium.

FRANK A. BRIDGETT. 

